Lyases;
Other lyases;
Sole sub-subclass for lyases that do not belong in the other subclasses
BRITE hierarchy

siroheme ferro-lyase (sirohydrochlorin-forming)

siroheme + 2 H+ = sirohydrochlorin + Fe2+ [RN:R02864]

R02864
Reaction

siroheme [CPD:C00748];
H+ [CPD:C00080]

This enzyme catalyses the third of three steps leading to the formation of siroheme from uroporphyrinogen III. The first step involves the donation of two S-adenosyl-L-methionine-derived methyl groups to carbons 2 and 7 of uroporphyrinogen III to form precorrin-2 (EC 2.1.1.107, uroporphyrin-III C-methyltransferase) and the second step involves an NAD+-dependent dehydrogenation to form sirohydrochlorin from precorrin-2 (EC 1.3.1.76, precorrin-2 dehydrogenase). In Saccharomyces cerevisiae, the last two steps are carried out by a single bifunctional enzyme, Met8p. In some bacteria, steps 1-3 are catalysed by a single multifunctional protein called CysG, whereas in Bacillus megaterium, three separate enzymes carry out each of the steps, with SirB being responsible for the above reaction.

EC 4.99.1.4 created 2004